With CATV (cable television) technology, it is extremely important to ensure that all connections are tight in order to prevent unwanted interference from getting into the transmission path. For bidirectional systems, it has been estimated that 70%-95% of the unwanted RF interference on the return path, from the subscriber to the headend, originates within the subscriber's premises or home. Because all the return signals funnel back into the headend, a single source of unwanted RF interference (RFI), also known as “ingress”, affects the service of all the subscribers. The RFI enters the system from improperly installed F-connectors, cracked or improperly shielded coaxial cable, or simply bad shielding around a television set's tuner. Improper installation includes the failure to tighten fully the connector into an equipment port, thus causing signal leakage and intermittent grounding.
Cable operators are spending enormous amounts of money and resources to maintain the headend plant free from the RFI caused by loose and improper connections. New digital products such as VOIP (voice over internet protocol) are extremely sensitive to RFI ingress. Small levels of ingress can disrupt voice service or cause dropped calls.